Getting an education was a bit like a communicable disease. It made you unsuitable for a lot of jobs and then you had the urge to pass it on.
Madness string 1979
If vampires don't need air, they would be awesome scuba divers. They could just wear a backpack full of rocks and walk on the bottom. And if they dive deep enough, light won't even reach down there. Like, aquatic vampire covens at the bottom of ocean trenches...